HERMAPHRODITISM IN MOLLUSCA. 43 



37. J. MuLLER. — 'Ueber Synapta digitata und die Erzengung von 



Schnecken in Holothurien,' p. 13. 



38. WiEEN. — " Studien iiber die Solenogastren," II, * K. Svensk. Vetensk. 



Akad. Handl.,' Bd. xxv, No. 6, p. 47. 



39. Davaine. — Loc. cit., p. 316. 



40. VAN Beneden. — ' Comptes Rendus Acad. Sci. Paris,' t. xl. 



41. Saint-Loup. — " Observations anatomiques sur les Aplysiens," ' Comptes 



rendus Acad. Sci. Paris,' t. cvii. 



42. FoL. — " Sur le Developpemeut de Pteropodes," ' Arch. Zool. exper.,' 



ser. 1, t. iv, p. 205. 



43. Trinchese. — " Descrizione del nuovo genera Bosellia," ' Mem. Accad. d, 



Sci. Bologna,' ser. 5, t. i, p. 776. 



44. ZiEGLER. — " Die Eutwickelung von Cyclas cornea, Lam.," 'Zeitschr. 



f. wiss. Zool.,' Bd. xli, p. 562, pi. xxviii, figs. 30, 33. 



45. Woodward.—' Proc. Zool. Soc London,' 1893, p. 321. 



46. KoRSCHELT and Heider. — 'Lebrbuch der vergleicbenden Entwickelungs- 



geschicbte der wirbellosen Thiere,' pp. 113, 119, 129, 223. 



47. This opinion, which I expressed several years ago for the MoUusca in 



general (' Comptes rendus,' t. ex, p. 1083), is also shared by Brock 

 for the Pulmonata (' Zeitschr. f. wiss. Zool.,' Bd. xliv, p. 374), and 

 has been since adopted by Lang (' Lehrbuch der vergleicbenden 

 Anatomic,' p. 816). 



48. E-OUZAUD. — 'Recherches sur le developpemeut des organes genitaux 



de quelques Gasteropodes hermaphrodites,' Montpellier, 1885, p. 79. 

 48a. Brock. — " Die Eutwickelung des GescLlechtsapparat der Stylommato- 



phoren Pulmonaten," ' Zeitschr. f. wiss. Zool.,' Bd. xliv, p. 368. 

 48b. Brock.— Loc. cit., pp. 372, 374. 

 48c. Peck. — " On the Anatomy and Histology ofCymbuliopsiscalceol a," 



' Stud. Biol. Lab. Johns Hopkins University,* vol. iv. No. 6, p. 15. 



49. von Jeering. — ' Jahrb. d. Malakozool. Gesellsch.,' Bd. xii, p. 207 (1885). 



SiMEOTH.—' Zeitschr. f. wiss. Zool.,' Bd. xlv, pp.655, 656, 661 (1887). 



49a. CoLLiNGE. — " Absence of Male Reproductive Organs in Two Herma- 

 phrodite MoUusca," ' Journ. of Anat. and Phys.,' vol. xxvii, p. 237. 



49b. CoLLiNGE. — Loc. cit., p. 238. 



49c. Beard. — " On the Life History and Development of the Genus Myzo- 

 stoma," 'Miltheil. Zool. Stat. Neapel,' Bd. v, p. 578 :—" Herma- 

 phroditism, probably all hermaphroditism, had its origin in a unisexual 

 condition." 



50. Delage. — " Involution de la Sacculine," ' Arch, de Zool. exper.,' ser. 2, 



t. ii, p. 704: — "La separation des sexes chez Sacculina, et probable- 



